The demand for multimedia content distribution services (e.g., live streaming and content-on-demand) has increased tremendously in recent years in view of the development of fixed and mobile broadband technologies and more and more powerful mobile handsets. To satisfy this explosive demand, and to overcome bandwidth and quality limitations associated with the use of centralized media servers, there is a need to deploy more and more edge servers close to the end users. One way to address this need is to use peer-to-peer (P2P) technology.
Generally, peer-to-peer technology relies on a distributed set of end-nodes (called peers) to interact with each other and share resources to perform some task or objective so as to reduce demands on centralized resources. For example, in the case of multimedia content distribution, peer-to-peer technology may be utilized to offload storage and bandwidth demands from centralized servers to edge servers and, to the extent end user equipment capabilities permit, to user equipment (UEs). In one example, the edge servers can handle media content requests from UEs served locally, as well as requests from neighboring edge servers. Similarly, if the UE's capabilities permit, UEs can offer spare uplink bandwidth, storage space and other resources to other peer UEs. In addition, the content can be transmitted in a segmented manner and most of the traffic can be spread across the edge of the network. All this contributes to reduced storage and bandwidth demands on centralized servers, as well as improved system capability that scales well with the increasing number of edge servers and UEs.
However, although P2P is a promising model for multimedia content distribution services, there are security issues that still need to be addressed. In one aspect, there is a need to verify content possession by end users (i.e., to verify that content advertised by a prospective content-supplier peer is indeed possessed by the advertising peer). This threat is addressed by related U.S. patent application Ser. No. 13/344,826. In another aspect, a threat exists following a successful advertisement of content that the announcing peer may maliciously (or perhaps mistakenly) share content with a receiving peer that is different in some way from the advertised or requested content. Accordingly, there is a need to verify integrity of peer-supplied content, for example, to verify that content supplied from a sending peer to a receiving peer corresponds to the content that was requested by the receiving peer.